Synthesis of sequentially deuterated 1‐n‐Butyl‐3‐methylimidazolium ionic liquids

Deuterium isotopologues of the ionic liquid (IL) 1–n‐butyl‐3‐methylimidazolium chloride (C₄mim]Cl) sequentially labeled on the C‐1″, C‐1′, C‐2′, C‐3′, and C‐4′ positions of the N‐alkyl groups were prepared following a strategy that minimizes the number of distinct reactions through the use of analogous synthetic routes. In several cases, good yields after the initial deuterium incorporation reaction were achieved by combining well‐established chemical transformations into efficient single‐step processes. Copyright © 2011 John Wiley & Sons, Ltd.